I just watched in its entirety the Milton Bradley at bat in the 5th inning, and the confrontation in the 8th.
According to Bradley, when he approached the batter's box in the 8th, the home plate umpire (Runge) asked him if he flipped his bat at the ump after he struck out in the 5th. Bradley says he told the ump "No, why would I do that?" Bradley then asked the ump "Who told you that?" Runge told him that Mike Winters, the first base ump told Runge that Bradley flipped the bat at him.
I watched the end of the at bat in the 5th. It was a called strike. The ump and the catcher moved away. Bradley stood at home plate taking off his batting gloves. He was annoyed, but he wasn't talking to Runge or acting in an angry manner. I certainly didn't see him throw the bat. It is possible he tossed it after they went to commercial, but that would have been a good 20 seconds after the strikeout, and Runge was no longer even in the camera shot. It seems highly unlikely.
So after the conversation with Runge in the 8th, Bradley singled. When he reaches first, he turns to Winters and asks him a question. Bradley says the question was "Did you tell him I threw my bat? Why would you do that?" In the video, Winters is responding calmly. Bradley says Winters is telling him "You did throw the bat." Watching the video, I'm guessing Winters' tone was more along the lines of "That's what I saw...I thought you threw the bat at him." Bradley is clearly upset. Todd Helton is stoic.
As several pitches are made to Kouzamanoff, Bradley is still jawing as he takes his leads. Black comes out of the dugout to find out what's going on and to have a talk with Winters. Also, first base coach Bobby Meacham tells Black what's going on.
The game resumes, with Bradley taking his lead more quietly on the next pitch. On the following pitch, Bradley is jawing again, but not in a particularly boisterous manner. He's just talking. A fan yells "You suck ump." Bradley points to the fan, but says nothing. He and Winters continue to exchange dialogue, though Bradley is talking a lot more than Winters.
In the middle of taking his next lead, Winters says something to Bradley, and Bradley snaps. He rushes back to the first base bag -- not at Winters -- and tries to ask for time out. He looks like he wants a time out to figure out what Winters' problem is. Before he gets to the bag he turns and heads for Winters, who quickly throws him out of the game as Meacham tries to restrain him. Then Bud Black is there -- out of nowhere -- wrestling Bradley away, and eventually twisting/tackling him to the ground, where Bradley tore his ACL.
Bradley is hot tempered and probably over reacted to the whole thing. He has a chip on his shoulder.
But when I watched the video, it is clear Winters said something special to push Bradley over the edge. He was not in charging mode while he was taking his leads and jawing. Winters said something that pushed him. I'd love to hear what that was, either from Bobby Meacham or Todd Helton. Meacham commented today that if Winters had said the same thing to him, he would have charged him too. No word yet from Helton.
Nate Silver at BP argues that Helton has an ethical duty to step forward and report what he heard.